A comparison of vitamin d levels in nondiabetic and diabetic patient populations.\nYoho RM, Frerichs J, Dodson NB, Greenhagan R, Geletta S.\nJ Am Podiatr Med Assoc. 2009 Jan-Feb;99(1):35-41.\nPMID: 19141720

Vitamin D Deficiency in Older Men.\nOrwoll E, Nielson CM, Marshall LM, Lambert L, Holton KF, Hoffman AR, Barrett-Connor E, Shikany JM, Dam T, Cauley JA; for the Osteoporotic Fractures in Men (MrOS) Study Group.\nJ Clin Endocrinol Metab. 2009 Jan 27. [Epub ahead of print]\nPMID: 19174492

Supplements of 20 microg/d cholecalciferol optimized serum 25-hydroxyvitamin D concentrations in 80% of premenopausal women in winter.\nNelson ML, Blum JM, Hollis BW, Rosen C, Sullivan SS.\nJ Nutr. 2009 Mar;139(3):540-6. Epub 2009 Jan 21.\nPMID: 19158226

I stumbled on one of the growing number of local media stories on the power of vitamin D. \nIn one story, a purported "expert" was talking about the benefits of "high-dose" vitamin D, meaning up to 1000, even 2000 units per day. \nI regard this as high-dose---for an infant. \nJudging by my experiences, now numbering well over 1000 patients over three years time, I'd regard this dose range not as "high dose," nor moderate dose, perhaps not even low dose. I'd regard it as barely adequate.

Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis.\nHolick MF.\nAm J Clin Nutr. 2004 Mar;79(3):362-71. Review. Erratum in: Am J Clin Nutr. 2004 May;79(5):890.\nPMID: 14985208

Vitamin D and cardiovascular disease risk. Michos ED, Melamed ML. Curr Opin Clin Nutr Metab Care. 2008 Jan;11(1):7-12. Review. PMID: 18090651

Vitamin D deficiency an important, common, and easily treatable cardiovascular risk factor?\nLee JH, O'Keefe JH, Bell D, Hensrud DD, Holick MF.\nJ Am Coll Cardiol. 2008 Dec 9;52(24):1949-56. Review.\nPMID: 19055985

Vitamin D and prevention of colorectal adenoma: a meta-analysis.\nWei MY, Garland CF, Gorham ED, Mohr SB, Giovannucci E.\nCancer Epidemiol Biomarkers Prev. 2008 Nov;17(11):2958-69.\nPMID: 18990737

Bioactive vitamin D or calcitriol is a steroid hormone that has long been known for its important role in regulating body levels of calcium and phosphorus, and in mineralization of bone. More recently, it has become clear that receptors for vitamin D are present in a wide variety of cells, and that this hormone has biologic effects which extend far beyond control of mineral metabolism. The active form of vitamin D binds to intracellular receptors that then function as transcription factors to modulate gene expression. Like the receptors for other steroid hormones and thyroid hormones, the vitamin D receptor has hormone-binding and DNA-binding domains. The vitamin D receptor forms a complex with another intracellular receptor, the retinoid-X receptor, and that heterodimer is what binds to DNA. In most cases studied, the effect is to activate transcription, but situations are also known in which vitamin D suppresses transcription. Each of the forms of vitamin D is hydrophobic, and is transported in blood bound to carrier proteins. The major carrier is called, appropriately, vitamin D-binding protein. The halflife of 25-hydroxycholecalciferol is several weeks, while that of 1,25-dihydroxycholecalciferol is only a few hours. The vitamin D receptor binds several forms of cholecalciferol. Its affinity for 1,25-dihydroxycholecalciferol is roughly 1000 times that for 25-hydroxycholecalciferol, which explains their relative biological potencies

The Linus Pauling Institute's Micronutrient Information Center is a source for scientifically accurate information regarding the roles of vitamins, minerals, other nutrients, dietary phytochemicals (plant chemicals that may affect health), and some foods